"Holy shit. I would be a horrible SAHM. One entire day with my kid makes me want to scream. And drink. And run away. I have completely disengaged. Horrible transition from part time mom during the week to full time mom on weekends."
Her son is 6.5.
The age information on her son is important, because 6.5 is a notoriously difficult phase for some kids and that is probably a contributing factor.
But I think a lot of this is the switch from, as Anon says, "part time mom during the week to full time mom on weekends." It's really difficult to switch your own energy from one mode to the other from work week to weekends. Having been a SAH mom for awhile and a WOH mom for awhile, the energy you use to get through your day (and week) is totally different, and if you're used to one kind it can be brutal to have to switch to the other.
So I DON'T think there's anything abnormal or horrible about you, and I do think some of this is just a function of a really annoying age, but I'm wondering if it might help a little to restructure weekends so your energy was redirected to give you some ease. One actual outing each day might be enough to add in the structure to shift the energy flow. Or, maybe even better, having playdates so your son gets to hang out with another kid and you get to hang out with another adult. (I found that a big part of the problem of being a WOH mom for me was being lonely. I was always either at work or with my kids and rarely had friend time.)
Does anyone have any sympathy or commiseration for Anonymous? I think this is especially difficult because there can be guilt about being a WOH mom already, so to be so frustrated and fried when you are home with your child feels like a big cluster.